I've changed both my Vanos Solenoids + flushed the engine with Liquid Moly Pro Line Engine Flush and changed the oil with Shell Helix Ultra 5W40...
What a difference, so much smoother + much better pick up in low RPM's.
That 'hick-up" I had in my dyno-graph around 1500RPM is gone
also the acceleration throughout the entire RPM range is much smoother and lineair.